Detent spring



March 16, 1965 Y. M. HOAG DETENT s am:

Filed Jan. 17, 1963 FIG.3.

FIG.2.

INVENTOR. YATES M. HOAG,

BY HIS ATTORNEY.

United States Patent 3,173,306 DETENT SPRING Yates M. Hoag, Utica, N.Y., assignor to General Electric Company, a corporation of New York Filed Jan. 17, 1963, Ser. No. 252,190 9 Claims. (Cl. 74-527) This invention relates to detent springs, such as are used for obtaining a detent action in electrical switches and the like, and partiiularly relates to detent springs of substantially fiat shape made from resilient sheet material.

The invention will be particularly described as used in an electrical switch of the sliding type in which a slidable contact member is located in a housing and is provided with a slide lever extending therefrom for manual actuation of the switch. In such a switch, a detent spring, comprising a substantially flat resilient member having an opening therethrough, is positioned over the slide lever and located between the slidable contact member and the housing so as to slide with the contact member. One or more detent dimples are provided on the detent spring, for selective engagement with one or more recesses in the housing. The resilient detent spring is given a slightly curved shape so that the detent dimples will resiliently engage the recesses.

The above described detent spring of the prior art is difficult to make for proper detent action, because of criticality of the thickness and resiliency of the spring material; A detent spring of a thickness to be sufliciently stiff for reliable detent action, makes it difficult to slide the switch. On the other hand, a detent spring that is sufficiently thin and resilient to provide a smooth and easy switch action, does not give a sufiiciently positive detent action for reliable manual positioning of the switch lever. Because of these considerations, the material for the detent spring must be carefully chosen for optimum results, and even with prudent care, the optimum results are not always entirely satisfactory. This ditiiculty increases as the size of the switch is made smaller.

An object of this invention is to provide an improved detent spring.

Another object is to provide a new detent spring having improved resiliency.

A further object is to provide a new detent spring for a slide switch, which will provide positive detent action and also enable the sliding contact member to slide easily. Still other objects will be apparent from the following description and claims and from the drawing in which:

'FIGURE 1 is a top view of a slide switch incorporating a preferred embodiment of the detent spring of the invention, shown partially broken away to better reveal the detent spring;

FIGURE 2 is a slide view of the switch of FIGURE 1, shown partially broken away along the line 2-2 of FIGURE 1 to better reveal the detent spring and switch construction;

FIGURE 3 is an end view of FIGURE 2; and

FIGURE 4 is a perspective view of the detent spring in accordance with the preferred embodiment of the invention.

In accordance with a preferred embodiment of the invention, a detent spring comprising a substantially flat resilient member having an opening therethrough, as described above, is provided with at least one slot therein extending into an end portion of the spring from an edge thereof and in a direction of movement of the slidable contact member. Preferably a plurality of such slots is provided as shown in the drawing and described hereinafter.

The slide switch shown in the drawing comprises a channel-shaped housing 11 made from sheet metal and having sides 12, 13 from which tabs 14, 15, 16 extend and are crimped against a base 18 of electrically insulative material to hold the base 18 across the open bottom of the channel-shaped housing 11. The base 18 carries a plurality of fixed electrical contact members each comprising a fixed contact at the upper side of the base and a connector terminal extending therefrom to a point beneath the base. In the particular switch shown, there are four contact members in each of two parallel rows. Contact members 21, 22, 23 and 24 are shown in one row, and one contact member 25 is shown of the other row of four contact members. The contact members extend through openings in the base 18 and are attached thereto by crimping as indicated at 26 and 27 in FIGURE 3.

The upper side of the housing 11 is provided with openings 28, 29 for riveting or otherwise attaching the switch in place.

A slidable contact member 31 is contained within the housing 11 and is provided with a slide lever 32 extending upwardly therefrom and through an elonagted opening 33 in the top of the housing 11. The top of the slide lever 32 may be serrated as indicated at 34 to facilitate manual sliding thereof by placing a finger against the serrated top. Alternatively, the switch may be actuated by manually gripping the lever 32 at its sides, to slide the contact member 31 to a desired position. A pair of elongated electrical contacts 36 and 37 are carried by the member 31 at the underside thereof, and are captivated thereby by means of upturned end portions 38, 39 which extend into openings 41, 42 of the member 31. Spring strips 43, 44 respectively urge the elongated contacts 36, 37 downwardly against the aforesaid rows of fixed contact members. When the slidable contact member 31 is in its various positions, the elongated contacts 36, 37 respectively electrically interconnect various pairs of the contact members 21, 22, 23, 24, etc. of each row in desired combinations.

A detent spring 51 is positioned between and in engagement with the slidable contact member 31 and the top 52 of the housing 11. The detent spring 51 is made from resilient sheet material, for example steel or Phosphor bronze. An opening 53 is provided through the detent spring, and the slide lever 32 extends through this opening 53 to captivate the detent spring with respect to the slidable member 31 so that the member 31 and detent spring 51 will slide in unison within the housing 11. The end regions of the detent spring bear against raised bearing portions 56, 57 of the member 31. The detent spring 51 is provided with upwardly struck detents 58, 59 which ride against the underside of the top 52 of the housing 11 and selectively engage and at least partially enter suitably placed notches or recesses 61, 62, 63 when the slidable mechanism is at its various operative positions, thus indicating to the operator-the operative positions by feel and by sound. These detents are centrally located in the side rails 64, 65 of the detent spring 51. In the preferred embodiment shown, one notch 61 is engaged by one detent 59 when the slide mechanism is at its leftmost position; another single notch 63 is engaged by the other detent 58 when the slide mechanism is at its rightmost position; and two notches 62 and a further notch (not shown) laterally across the slot 33 from the notch 62 are simultaneously and respectively engaged by the detents 58 and 59 when the slide mechanism is at its middle position. This arrangement provides a relatively more positive detent action when the slide mechanism is at its middle position, and relatively less positive detent action when at either of its end positions. The end positions of the slide mechanism are further defined by the slide lever 32 engaging the ends of the opening 33.

The detent spring 51 is substantially flat and may be U made slightly curved, as shown, to enhance the detent action.

As described above in the third paragraph hereof, the detentspring is critical as to the relationship between its thickness and resiliency for obtaining proper detent action and for enabling a smooth and easy sliding action of the switch.

In accordancewith the invention, the detent spring is improved by providing one or more slots 66, 67, 68, 69, 70 and 71 extending longitudinally into the body 72'of the spring from edges thereof. In the preferred embodiment shown, slots 66 and 67 extend longitudinally into one end of the body 72 from the inner edge thereof, this inner edge being defined by the opening'53. Slots 68 and 69 extend longitudinally into the other end of the body 72 from the inner edge thereof. The slots 66-69 preferably are substantially in line with and form extensions of the inner edges of the side rails 64 and 65, as shown. This increases the effective lengths of the side rails and thus increases their resiliency. The slots 70 and 71 extend longitudinally into the body 72 from the outer edge thereof at the respective ends, as shown, and are located substantially on the central axis of the detent spring. These slots 70 and 71-increase the resiliency of the end regions of the spring and provide relatively greater independent action of the side rails 64, 6S and their detents 58, 59.

By providing the aforesaid slots 66-71, in accordance with the invention, the objects of the invention are achieved.

Although the preferred embodiment of the invention provides six slots in the detent spring, it is found that fewer slots can be employed, to provide a lesser improvement in the detent spring. For example, the outer slots 70 and 71 may be omitted, in which event the detent spring, provided withthe slots 66-69, willhave slightly less overall resiliency and less independent action of the side rails 64, 65, and hence will have slightly less improved detent or sliding proficiency than the preferred embodiment. Also, it is found that if the slots 6669 are omitted, leaving only the end slots 70 and 71, the detent action of the spring is substantially reduced from that of the preferred embodiment, but is an improvement over such a detent spring having none of the slots 6671.

While a preferred embodiment of the invention and modifications thereof have been shown and described, various other embodiments and modifications will be apparent to persons skilled in the art involved, and will fall within the scope of invention as defined in the following claims.

What is claimed is:

1. A detent spring for a mechanism having a movable element, comprising a detent member made from resilient sheet material and provided with a cut-out portion to fit around said movable element to captivate said detent member for movement with said movable element, and a detent located in a side portion of said member, said member being provided with at least one slot therein extending from an edge thereof in a direction parallel to said side portion,

2. A detent spring for a mechanism having a slidable element, comprising a detent member made from resilient sheet material and provided with an opening therethrough to fit around a portion of said slidable element to captivate said detent member for movement with said slidable element, at least one of the side portions of said member being provided with a detent, and said member being provided with at least one slot therein, extending from an edge thereof in a direction parallelto said side portions.

3. A detent spring as claimed in claim 2, in which said member is provided with four slots extending therein from said opening, a first pair of said slots extending in one direction parallel to said side portions and respectively in substantial alignment with the inner edges of the side portions of said member, and a second pair of said slots extending in the opposite directionfrorn said one direction and respectively in substantial alignment with said inner edges of said side portions.

4. A detent spring as claimed in claim 3, in which said memberis provided with an additional slot extending therein from one end thereof and a further additional slot extending therein from the other end thereof, said additional slots lying respectively between the slots of said pairs of slots.

5. A detent spring as claimed in claim 2, in which said member is provided with slots respectively extending therein from the ends thereof, said last-named slots lying on a line extending between said side portions.

6. A-detent spring comprising a substantially flat resilient member having two end portions and two side portions defining an opening therethrough, at least one of said side portions being provided with a detent, and said member being provided with at least one slot therein extending from an edge thereof into one of said end portions in a direction substantially parallel to aline extending through said end portions.

7. A detent spring asclaimed in claim 6, in which said member is provided with a first pair of slots extending into one of said end portions from said opening and respectively in substantial alignment with the inner edges of said side portions, and a second pair of slots extending into the other of said end portions from said opening and respectively in substantial alignment with said inner edges of said side portions. i

8. A detentspring as claimed in claim 7, in which said member 'is provided with an additional slot extending therein from one end thereof and a further additional. slot extending therein from the other end thereof, said additional slots lying respectively between the slots of said pairs of slots. g

9. A detent spring as claimed in claim 6, in which said member is provided with slots respectively extending therein from the ends thereof, said last-named slots lying on a line extending between said side portions.

References Cited by the Examiner UNITED STATES PATENTS 2,528,115 10/50 Clayton 74 527 X BROUGHTON Primary Examiner. 

1. A DETENT SPRING FOR A MECHANISM HAVING A MOVABLE ELEMENT, COMPRISING A DETENT MEMBER MADE FROM RESILIENT SHEET MATERIAL AND PROVIDED WITH A CUT-OUT PORTION TO FIT AROUND SAID MOVABLE ELEMENT TO CAPTIVATE SAID DETENT MEMBER FOR MOVEMENT WITH SAID MOVABLE ELEMENT, AND A DETENT LOCATED IN A SIDE PORTION OF SAID MEMBER, SAID MEMBER BEING PROVIDED WITH AT LEAST ONE SLOT THEREIN EXTENDING FROM AN EDGE THEREOF IN A DIRECTION PARALLEL TO SAID SIDE PORTION. 